'''alien_0 = {'color': 'green', 'points':5}
print(alien_0)
#alien_0 = {'x_position':0, 'y_position':25}
#print(alien_0)
alien_0['x_position'] =0
alien_0['y_position']=25
print(alien_0)'''

'''alien_0={}
alien_0['x_position']=0
alien_0['y_position']=25
print(alien_0)
print(f'the x_position is {alien_0['x_position']}')
alien_0['x_position']=66
print(F'the new x_position is {alien_0["x_position"]}')
print(alien_0)
del alien_0['x_position']
print(alien_0)'''

'''hahah={
    'color':'green',
    'a':2,
    'b': 3
}
print(hahah)
nicc=hahah.get('c','没有')

print(nicc)'''

'''xy={
    'a':1,
    'b':2,
    'c':30,
    's':2,
}
for key,value in xy.items():
   # print(key,value)
    print(f'\nkey:{key}' )
    print(f'value:{value}' )
for zz in xy:
    print(zz)
for aa in set(xy.values()):
    print(aa)
for bb in xy:    '''

cities={
    'NC':{
        'country':'中国',
        'population':1000,
        'fact':12
    },
    'NY': {
        'country': '美国',
        'population': 2000,
        'fact': 13
    },
    'XN': {
        'country': '澳大利亚',
        'population': 500,
        'fact': 14
    }
}
for city,city_info in cities.items():
    print('\n城市名称',city)

    print('城市人口',city_info['population'])
    print('城市fact',city_info['fact'])













